Commercial Hydronics Future?

Hilly

I know air-to-water, geo and solar are some options when consumers are looking to reduce carbon footprint. More companies are bringing out products and a lot are lower output in both the temperature range and BTU/h capacity that will clearly be targeted at a residential market.

What might some of the solutions be for large multi-unit residential that have high temperature baseboard fin/tube and large domestic hot water demands when these clients have future carbon taxes to worry about and have net-zero goals and/or deadlines?

I'd love to hear if anyone has opinion in theory and/or practice.

Hot_water_fan

I’d expect multiple air-to-water heat pumps operating in parallel. Add in/keep the existing fossil backup and you’re good to go. 

Jamie Hall

I'd agree with @Hot_water_fan fan. As time goes on, air to water heat pumps may become capable of higher temperature outputs, which will help, but they are not yet at the point where they alone can handle the type of loads you are facing.

If your jurisdiction allows keeping the fossil fuel, you will need to get more savvy as to determining the relative costs of running the fossil fuel units and replacing them or supplementing them. This is a complex calculation, and not one we as a trade are particularly used to -- or comfortable with.

Of course if your jurisdiction flat out prohibits new or replacement fossil fuel installations, just give the tenants blankets and have them send out for coffee.

RayWohlfarth

The age of fossil fuel boilers for comfort heating are fading quickly which means you have to hope you can install a boiler before they are banned. The issue with the system you are mentioning is the the original design temperature for it was 180 degrees F That temperature is only required on the very cold days but that is when you need the heat the most. If you want to use a lower temperature for heating, you will need to add more capacity. I guess you could look at insulating the building better which would limit the heat loss. Either way its going to be cold or expensive

Larry Weingarten

Hi, Thinking long term, probably tightening up the shell of the building will allow cooler water to be used for space heating. This could be supplied by a combination of solar thermal and HP. For domestic hot water, drain water heat recovery can do half of the heating. Preheat with the same solar thermal and finish with a HP. This DHW heating becomes easier if we reduce use with right sized piping and low flow fixtures and appliances. None of this is cheap 🤑
Yours, Larry

leonz

I am happy with my coal stoker boiler, and it costs very little to heat my old leaky home on average and make Domestic Hot Water, I use 50 pounds of Anthracite Rice Coal per day on average.

jumper

I remember home buyers in all electric subdivisions believing that electric energy will become less expensive than oil or gas. That was in seventies when OPEC tripled petroleum price. Twice. I also remember tall buildings with "all air" systems.

leonz

Hilly said:

I know air-to-water, geo and solar are some options when consumers are looking to reduce carbon footprint. More companies are bringing out products and a lot are lower output in both the temperature range and BTU/h capacity that will clearly be targeted at a residential market.

What might some of the solutions be for large multi-unit residential that have high temperature baseboard fin/tube and large domestic hot water demands when these clients have future carbon taxes to worry about and have net-zero goals and/or deadlines?

I'd love to hear if anyone has opinion in theory and/or practice.

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Live Better Electrically and Ready Kilowatt were your friends.

Using overhead hot water heat or overhead steam heating would be my choice due to its simplicity.
No need to bleed air and it provides smooth even heat.

They are heating many upgraded homes in Europe with 160 degree water using wood pellets so they are managing thier heating needs as they are well insulated and many of them have Russian and Finnish stone fireplaces with multiple long passages to burn the smoke and heat the stone that they are made of.